def Inverse_Proportion(N):
    retu=[]
    for i in range(1,N+1):
        if i==N or N//i>N//(i+1):
            retu.append(((i,i+1),N//i))
        else:
            for j in range(N//i,0,-1):
                retu.append(((N//(j+1)+1,N//j+1),j))
            break
    return retu

N=int(input())
IP=Inverse_Proportion(N)
ans=len(IP)
print(ans)